KEW 1: Back to basics
“An investment in knowledge pays the best interest.” ― Benjamin Franklin
Last week I posted that I’d like to learn something new about Kubernetes every week. As tempting as it is to dive straight into getting hands-on, I want to take time to learn the fundamentals. I recently purchased Kubernetes in Action by Marko Lukša and Kevin Conner.
My plan is to read a couple of chapters each week. The book teaches Kubernetes by building a project, so there should be plenty of chances to get hands-on too.
This week I read chapters 1-3. The first chapter gives an introduction to Kubernetes. This covers how the project came about, the basic architecture of a Kubernetes cluster and the different ways it can be run, as well as if you should even consider running it in the first place. I enjoyed this chapter. The authors did a good job of giving just enough detail without going too far and losing me.
Chapter 2 covered containers and running containerised applications. I’ve used Docker a lot throughout my career, so I was tempted to skip this chapter, but I’m glad I didn’t. I learnt a few new things about image layers, like how filesystems are isolated between containers via a copy-on-write mechanism. I also learnt about the Open Container Initiative (OCI) and Container Runtime Interface (CRI) that allow different container runtimes such as containerd or CRI-O to be used by Kubernetes. The chapter closed by explaining how containers are isolated from each other using namespaces and how control groups can limit resource usage.
Chapter 3 is the first opportunity to get hands-on by deploying an application on Kubernetes. I only read through the chapter this week and plan to go back and do the exercises next week which include running a Kubernetes cluster locally and in the cloud.
I’m happy with what I’ve done this week. I’ve learnt a few new things and reminded myself of lots I forgot I knew at some point in the past!